Elastomeric Networks, and Their Use in Novel Nanocomposites and Related Materials

技术总结：正在进行的研究的一个实际目标是获得可用于优化弹性体材料性能的结构-性能关系。实验将包括各种变形，并将进行相应的计算机模拟。 弹性体将包括通过各种技术交联的商业上重要的聚合物。一个具体的项目将是生产可生物降解的弹性凝胶，增强方向和改善机械性能。 另一个例子涉及应变诱导结晶的表征，这可以大大提高材料的机械性能。新的增强填料如二氧化硅将原位生成，产生不寻常的颗粒形状和取向，一种类型的陶瓷颗粒将被另一种类型的陶瓷包覆。还可以将弹性体链穿过增强沸石，以获得其他不寻常的性能。模拟也将进行阐明填充弹性体中的增强机制，这是聚合物科学这一领域中尚未解决的主要问题之一。这里特别感兴趣的是当初级颗粒结合成称为“聚集体”的相对稳定的结构和称为“附聚物”的不太稳定的排列时获得的增强的类型和程度。作为最后一个主题，将进行实验，以利用弹性域的能力，以提高聚合物-陶瓷混杂复合材料的耐冲击性，其中陶瓷是连续相。在这方面，特别感兴趣的是通过使用网络结构的连接性在一个阶段中的分散水平的控制，以“挫败”在不同的双组分系统中的相分离的通常类型。 非技术总结：所描述的工作将提供更好地理解一般的聚合物和弹性体和纳米复合材料，特别是。这将最终导致对更好的弹性体材料和各种类型的复合材料的制备和利用的重要指导。研究结果将以通常的方式在期刊出版物和各种科学或工程学会的全国会议上发表。 更广泛的影响，将包括整合研究和教学。弹性体材料所表现出的橡胶般的弹性是它们最显著的特征之一，申请人将继续在讲座中的演示、实验室课程中的实验以及标准物理化学概念的修改中利用这一点。在这些项目中获得的实验、模拟和理论结果将继续包括在辛辛那提大学教授的弹性课程中，以及申请人自1972年以来教授的一些美国化学学会短期课程中。

TECHNICAL SUMMARY:One practical goal of the research being carried out is to obtain structure-property relationships that can be used to optimize the properties of elastomeric materials. Experiments will include a variety of deformations, and corresponding computer simulations will be carried out as well. Elastomers will include commercially important polymers, cross linked by a variety of techniques. One specific project will be producing biodegradable elastomeric gels of enhanced orientation and improved mechanical properties. Another example involves characterization of strain-induced crystallization, which can greatly improve the mechanical properties of a material. Novel reinforcing fillers such as silica will be generated in-situ, yielding unusual particle shapes and orientations, and ceramic particles of one type will be coated by a ceramic of another type. It will also be possible to thread elastomeric chains through reinforcing zeolites, to obtain other unusual properties. Simulations will also be carried out to elucidate reinforcing mechanisms in filled elastomers in general, which is one of the major unsolved problems in this area of polymer science. Of particular interest here is the types and extents of reinforcement obtained when the primary particles are bonded into relatively stable structures called "aggregates" and into less-stable arrangements called "agglomerates". As a final topic, experiments will be carried out to exploit the ability of elastomeric domains to improve the impact resistances of polymer-ceramic hybrid composites in which the ceramic is the continuous phase. Of particular interest in this regard is control of the level of dispersion by using the connectivity of network structures in one of the phases to "frustrate" the usual types of phase separation in disparate two-component systems. NON-TECHNICAL SUMMARY:The work described will provide a better understanding of polymers in general and elastomers and nanocomposites in particular. This will ultimately lead to guidance important for the preparation and utilization of better elastomeric materials and various types of composites. Results will be disseminated in the usual way, in journal publications and lecture presentations at National Meetings of various scientific or engineering societies. Broader impacts, would include integrating research and teaching. The rubberlike elasticity exhibited by elastomeric materials is one of their most striking features, and the applicant will continue to exploit this in demonstrations during lectures, experiments in laboratory courses, and in the modification of standard physical chemistry concepts. Results from experiments, simulations, and theory obtained in these projects will continue to be included in the elasticity course taught at the University of Cincinnati, and in some of the American Chemical Society Short Courses the applicant has taught since 1972.